Detection of cancer at early stages is critical for curative treatment interventions. While the five-year disease free survival for UICC stage I tumors exceeds 90%, this percentage is reduced to 63% in UICC stage III carcinomas (O'Connell J B, Maggard M A, Ko C Y. Colon cancer survival rates with the new American Joint Committee on Cancer sixth edition staging. J Natl Cancer Inst 2004; 96: 1420-1425). Tools and methodologies for early cancer detection directly impact survival times.
Late diagnosis of colorectal carcinomas results in a significant reduction of average survival times. Yet, despite screening programs about 70% of tumors are detected at advanced stages (UICC III/IV).
In present clinical practice, for example, screening for cancer and pre-invasive polyps of the colorectum is based on clinical examination, the detection of fecal occult blood (FOBT), and on sigmoidoscopy or colonoscopy (Mak T, Lalloo F, Evans D G, Hill J. Molecular stool screening for colorectal cancer. Br J Surg 2004; 91:790-800). The successful implementation of these screening procedures has contributed to a modest reduction of the mortality of colorectal carcinomas (Fleischer D E, Goldberg S B, Browning T H, Cooper J N, Friedman E, Goldner F H, Keeffe E B, Smith L E. Detection and surveillance of colorectal cancer. Jama 1989; 261:580-585). However, colonic tumors still rank among the most common malignant cancers in the Western World and present a major health care problem. Approximately 140,000 new cases are diagnosed in the U.S. annually, and about 55,000 subjects die of the disease (Schulmann K, Reiser M, Schmiegel W. Colonic cancer and polyps. Best Pract Res Clin Gastroenterol 2002; 16:91-114). The high mortality is attributable to a low compliance to some screening tests (e.g., colonoscopy) or to the low sensitivity of others (e.g., FOBT) (Schulmann, et al.).
Current methods for early detection, diagnosis, prognosis, and treatment of cancer fails to satisfactorily reduce the morbidity associated with the disease. There is thus a need in the art for further reduction of mortality rates, and early cancer detection in minimally invasive, cost efficient formats.